6 BIILLETIISr 1104, U. S. DEPARTMENT OF AGRICULTURE. 



EXPERIMENTAL WORK. 



Previous to the time the present writers took up the work on 

 internal browning considerable attention had been given to obtain- 

 ing individual tree records from a number of orchards in the 

 Pajaro Valley. This work has been continued and modified in some 

 respects. Most of the work has been confined to orchards on the floor 

 of the valley, but sufficient data have been obtained from trees grow- 

 ing at higher elevations, in the so-called mountain orchards, to 

 establish a definite contrast in the susceptibility to internal brown- 

 ing of the two types of fruit. In addition fruit from a number of 

 individual Yellow Newtown trees in the Yakima and Wenatchee 

 Valleys of Washington and in Albemarle County in Virginia have 

 been shipped to Watsonville and held in storage for comparison 

 with the locally grown fruit. In this experimental work some at- 

 tention has been given to the Red Pearmain variety, but for the most 

 part the investigations have been confined to the Yellow Newtown, 

 because of its greater commercial importance. Trees under obser- 

 vation have been marked by numbered indestructible metal tags. 

 At picking time the desired quantity of fruit from each tree has 

 been packed in commercial apple boxes and the boxes marked with 

 the tree and orchard number. After picking, the fruit practically 

 always has been placed in cold storage within 24 to 36 hours. 



The fruit from the various orchards was picked each year at the 

 time when the commercial harvesting was in progress in the par- 

 ticular orchards, and an attempt was made to gather apples from 

 all parts of the tree, so that each box represented as nearly as pos- 

 sible a uniform sample of the crop on the tree. Usually, when only 

 a record of internal browning was wanted, a single box was all that 

 was taken from a tree. If it was desired to compare the effect of 

 various storage temperatures on fruit from a certain tree or if 

 larger quantities were wanted for experimental work, the required 

 quantity was picked and carefully mixed before packing, in order 

 to insure as far as possible a uniformity of fruit throughout the 

 entire number of boxes. 



During the progress of the investigations with which the present 

 writers have been concerned, more or less continuous records have 

 been obtained from a total of about 150 trees. During that time 

 about 800 boxes of fruit have been carefully examined, and for the 

 most part a record of the internal browning in each individual apple 

 has been made. 



The fruit has usually been left in storage until May or June, to 

 allow the maximum development of internal browning. At the time 

 of inspection the apples were examined as soon after removal from 

 storage as possible, and in no case was the fruit taken from storage 



